Smoke billows from an apartment building in Bongcheon-dong, Gwanak-gu, Seoul, after a fire caused by arson using a pesticide sprayer filled with flammable liquid on April 21. Yonhap News

A man in his 60s died after setting fire to the apartment building where he once lived, using a pesticide sprayer filled with flammable liquid. Two women in their 70s and 80s sustained serious injuries after falling from windows while trying to escape the flames. Neighbors reported that the man had conflicts with upstairs residents over the issue of noise between floors.

According to Seoul’s Gwanak Police Station and fire authorities, a fire broke out around 8:17 a.m. on April 21 at an apartment complex in Bongcheon-dong, Gwanak-gu, Seoul. The blaze was extinguished about an hour later, at 9:25 a.m., but it left one person dead, two seriously injured, and nine others with minor injuries.

The fire occurred in a 21-story apartment building, which is a rental apartment building in a complex that is mostly occupied by the elderly and low-income residents. The fire started on the fourth floor, where flames erupted from two units, shattering windows with loud explosions. One witness said, “Shards of glass fell like snow and were blown as far as 15 meters away to a nearby playground.”

According to the police investigation, the fire was deliberately set by a man in his 60s, referred to as Mr. A, who used a pesticide sprayer filled with flammable material. He is believed to have broken windows facing the corridor of units 401 and 404 and ignited the fire inside. Two elderly women who lived in the affected units were seriously injured after hanging from their windows and falling. A resident across the way, Mr. Kim, said, “I saw one person hanging from the railing, and another who had been hanging outside a neighboring unit fell.”

After the fire was extinguished, a burned body was found in the hallway on the fourth floor. Police confirmed through CCTV footage and fingerprint analysis that the deceased was Mr. A. His motorcycle was found in the apartment’s underground parking lot, loaded with two containers of flammable liquid.

The two burned units, 401 and 404, were separated by other two units between them, which led authorities to suspect arson rather than an accidental fire from the beginning. Mr. A had previously lived on the third floor of the same building until early November last year. Around September, he reportedly got into a dispute with fourth-floor residents over noise between floors, and the police were called.

A third-floor resident told reporters, “I heard he was evicted last year for reasons related to inter-floor noise. He even knocked on a neighbor’s door with a hammer, yelling it was too noisy.” However, it remains unclear whether he was officially evicted for that reason.

The police are also investigating the possibility that Mr. A may have had a motive other than the noise, as units 401 and 404 are on the same floor but separated from each other.

Mr. A appeared to have meticulously planned the arson. At around 7:50 a.m., just before the apartment fire, he used the pesticide sprayer to set fire to the front gate of a multi-unit house near his current residence, about 1.5 kilometers away from the apartment. This was in front of the multi-unit house where he lived with his mother.

A resident of the multi-unit house said, “I saw him spraying a transparent liquid on the wall and thought he was disinfecting, but then he suddenly set it on fire.” Another resident managed to extinguish the flames with a fire extinguisher, while Mr. A calmly drove off on his motorcycle without saying a word. Fortunately, the fire at the house did not spread much. The police suspected that Mr. A had set the fire in advance to test whether the blast device worked properly.

Neighbors said Mr. A often had poor relationships with others. A 21-year-old resident surnamed Shin said, “I saw him swearing and spitting at other people,” adding, “He made a lot of noise between floors, swore, argued and pushed others around.” Another resident said, "When the vegetable vendor would drive by in his truck and broadcast his commercials, he would curse out the window, saying it was 'too loud.’”

According to the police, a suicide note and 50,000 won in cash were found in Mr. A’s home. The note reportedly read, “I’m sorry to my family. Please use this for my mother’s hospital bills.”